Process of making acid-proof alloys and product thereof



Patented May 25, 1926.

UNITED STATES JOHN P. KEGG, OF PITTSBURGH, PENNSYLVANIA.

PROCESS OF MAKING ACID-PROOF ALLOYS AND PRODUCT THEREOF.

Ili'o ZDrawing.

My invention relates to alloys, and it has for its object to provide an alloy which shall be highly resistant to the action of acids and other corroding agents.

' More specifically my object is to provide an acid-proof alloy containing copper and lead, with or without tin, in which relatively large amounts of lead may be used and in which the lead shall be held up and dlstributed uniforlr ly in the metal.

In making my improved alloys I employ as an agent for preventing segregation of the lead a small amount of an alkali metal, suitably metallic sodium or metallic potassium. The sodium or potassium are not intended to remain in the final metal. Thus, if sodium is used the final alloy contains substantially no trace of sodium, which apparently volatilizes off while thealloy is being stirred and poured.

One useful alloy which I have made in accordance with this invention may be made by melting the following ingredients in about the proportions specified:

Parts by weight.

Copper 300 Lead 175 Tin 25 Metallic sodium 1 mixing. The melted metal is heated high' enough to be very fluid and the alloy is preferably poured as quickly as practicable after the sodium is added.

On analysis, the alloy prepared in the manner just described shows substantially no sodium, but contains the other ingredients in about the original proportions, w1th only such trifling losses as occur in ordinary foundry practice. Thus, the final alloy may be regarded as having the following approximate composition: copper lead 35%, tin 5%. This alloy resembles copper in color, but is harder and exceedingly tough, wholly resists the corroding action of sulphuric acid and other acids, and is Application filed February 28, 1922. Serial No. 539,915.-

homogeneous in structure, the lead being distributed uniformly and held in such a manner that the lead will not segregate or sweat added. This gives an acid-proof alloy con- 4 taining approximately 50% of copper and 50% of lead, with the lead held up and distributed uniformly in the metal.

I-wish it to be understood that the proportions mentioned above are given only as examples of my process, and that my invention is not restricted to the proportions stated but consists broadly in the use of metallic sodium,metallic potassium or other metallic alkali metal as an agent for producing a homogeneous acid-proof. alloy from copper and lead with or without tin. The. lead may be present in any proportion up to 50%, or even higher, of the finished alloy. The treatment with sodium or other alkali metal holds up any smaller quantity of lead,

and is particularly useful when the lead constitutes 20% to 50% of the alloy. The amount of sodium to be used depends somewhat on the purity of the lead that is used. With verypure lead one part of sodium to 100 parts of the other ingredients is sufficient for my purpose, while with impure lead 1% to 2 parts will be required.

- I am aware that many attempts have been made to produce alloys of copper, lead and tin, containing large proportions of lead, and that various agents have been added to such alloys for the purpose of distributing the lead and preventing it from segregating as it tends to do is present in any considerable quantity. I am also aware that it has been proposed to add to an alloy of copper, lead and tin a small amount of sodium to increase the fluidity of the alloy and facilitate casting it into small articles. The prior alloy just mentioned, however, makes use of a wholly different material for the purpose of holding up the lead, and the possibility of holding up lead in an alloy of this kind by means of sodium or any other. alkali metal has notbeen recognized prior; to my invention.

I am not prepared to state exactly the holding the lead in s manner in which the sodium or potassium vpotassium. What I know to be a fact is that when sodium or potassium is used the preparation of an alloy in the manner herein described, the resulting alloy is tougher, more resistant to the action of acids and more homogenous, especially as to thedistribution of load, than the corresponding alloys would be if made without the use of alkali metal. v I claim as my invention: 1. The process of making alloys that comri'ses' melting copper and lead together, the ead being present in such quantity as tends to segregate from the other constituents, and adding an alkali meal to the melt, thereby spension therein. 2. The lprocess of making alloys that comprises me ting copper, lead and tin together,

the lead being present in such quantity as tends to segregate from the other constitu-- ents, and adding an alkali metal to the melt, thereby holding the lead in suspension therein.

3. The process of making alloys that comrises me ting copper and lead together, the cad being present in such quantity as tends to segregate from the other constituents, and adding metallic sodium to the melt, thereby holding the lead in sus ension therein.

4. The rocess'of ma 'ng alloys thatcomprises me ting copper, lead and tin together, the lead being present in such quantity as tends to segregate from the other constituents, and a ding metallic sodium to the melt, thereby holding the lead in I suspension therein.

5. The rocess of making alloys that comv prises me ting copper and lead together, the

lead being present in such uantity as tends to segregate from the .ot er constituents, and adding an alkali metal to the melt,

thereby holding the lead in suspension therein, said alkali metal being added in prises melting copper, lead and tin together,

the lead being present in such quantity as prises melting copper and lead together, the I lead being present in such quantity-as tends to segregate from the other constituents, and adding metallic sodium to the melt, thereby holding the lead in suspension therein, said alkali metal being added insuch quantity as not to form a substantial ingredient in the final alloy.

8. The process of making alloys that comprises me t the lead being present in such quantity as 1 tends to segregate from the other constituents, and adding metallic sodium to the melt, thereby holding the lead in suspension therein, said alkali metal being added in such quantity as not to vform a substantial ingredient in the final alloy.

9. The process of making alloys that comprises melting a quantity of copper, adding lead to the melted copper, heating the melt 'sufiiciently to make it flow freely, adding a small quantity of an alkali metal to the melt and pouring the mixture immediately after the addition'of said alkali metal.

10. The process of making alloys that comprises melting a quantity of copper, adding lead to the melted copper, adding tin to the melted mixture, heatmg the melt suf ficieutlyto'make it flow freely, adding a small quantity of an alkali metal to the melt and pouring the mixture immediately after the additionof said alkali metal.

11. The process of making alloys that comprises melting tbgether substantiallyfl300 parts by weight of copper, 175 parts by weight of lead, and 25'parts by weight of tin, adding to the molten metal approximately 1 part by weight ofmetal'lic sodium and then pouring the molten metal.

In testimony whereof, I the said J OHN P.

Knee have hereunto setmy hand. I

JOHN P. nee.-

ing copper, lead and tin together, 

